#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e3+100;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
vector<LL>g[maxn];
LL du[maxn];
LL ask(LL u,LL v){
   cout<<"? "<<u<<" "<<v<<endl;
   LL ans;cin>>ans;
   return ans;
}
void pri(LL u){
   cout<<"! "<<u<<endl;
}
int main(void){
   ///cin.tie(0);std::ios::sync_with_stdio(false);
   LL n;cin>>n;
   for(LL i=1;i<n;i++){
      LL u,v;cin>>u>>v;
      du[u]++;du[v]++;
      g[u].push_back(v);g[v].push_back(u);
   }
   queue<LL>que;
   for(LL i=1;i<=n;i++){
       if(du[i]==1){
          que.push(i);
       }
   }
   while(!que.empty()){
        LL leaf1=que.front();que.pop();
        if(que.empty()){
            pri(leaf1);break;
        }
        LL leaf2=que.front();
        LL ans=ask(leaf1,leaf2);que.pop();
        if(ans==leaf1){
            pri(leaf1);
            break;
        }
        if(ans==leaf2){
            pri(leaf2);
            break;
        }
        for(auto i:g[leaf1]){
            LL v=i;
            if(--du[v]==1){
                que.push(v);
            }
        }
        for(auto i:g[leaf2]){
            LL v=i;
            if(--du[v]==1){
                que.push(v);
            }
        }
   }
   return 0;
}
